<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title>5-5</title>
    <style>
        #box{
            position:absolute;
            top:50%;/*居中*/
            left:50%;
            color:#fff;
            width:200px;
            height:200px;
            background:red;
            cursor:pointer;
            letter-spacing:5px;
            text-align:center;
            font:12px/200px Arial;
            margin :-100px 0 0 -100px;
        }
    </style>
    <script>
        window.onload = function () {
            var oBox = document.getElementById("box");
            var timer = null;

            oBox.onclick = function () {
                var i = 0;
                clearInterval(timer);
                timer = setInterval(function () {
                    oBox.style.display = i++ % 2 ? "none" : "block";
                    i > 6 && (clearInterval(timer));
                }, 80);
            }
        };
    </script>
</head>
<body>
<div id="box">点击我就闪</div>
</body>
</html>